一种抑制扰动的轴向磁轴承鲁棒控制新方法

Robust control method for disturbance rejection on axial magnetic bearing

从鲁棒稳定性和抑制扰动的动态性能角度,分析了干扰观测器应用到轴向磁轴承时其有效带宽较低的问题,指出磁轴承易受到低频干扰并提出了一种抑制扰动鲁棒控制方法.基于动态分析建立了轴向磁轴承的名义模型,并设计了内环控制的干扰观测器,采用标准H∞问题的方法设计抑制扰动鲁棒控制器作为外环控制.仿真分析与实验说明了该方法能够提高干扰观测器的带宽,同时,实验验证了对于系统参数不确定性具有较强的鲁棒性能,对比单一的控制方法具有良好的抑制扰动能力.

Considering the requirements of robust stability and dynamic performance to reject disturbance,the problem of low bandwidth was analyzed when applying the disturbance observation（DOB） in the magnetic bearing.It was pointed out that the magnetic bearing was affected by outside low bandwidth noise,then a robust disturbance rejection method was proposed.The nominal model of the axial magnetic bearing was set up through dynamic analysis.And the DOB for internal loop controller was designed consisting of the inverse nominal model and a low pass filter with two relative rank.In external loop,a robust controller is developed using standard H∞ analysis method after choosing proper weight functions to enhance robust stability.The simulation analysis and experiment result indicate that the method could extend the bandwidth of the DOB.Comparing to single controller,experimental result verifies that the robust disturbance rejection system controller has broad robust stability margin on parameter uncertainty and strong ability to eliminate disturbance.